In the development phase the teacher is provided with several examples to demonstrate solving equations using the quadratic formula for positive and negative values of a, b and c.

Further on, the students have the opportunity to practise this for themselves. The plenary involves deriving and applying the formula to calculate unknown lengths when given the area of a trapezium.

**Differentiated Learning Objectives**

- All students should be able to use the quadratic formula to solve quadratic equations where the coefficient of a = a and are equal to zero.
- Most students should be able to solve a quadratic equation using the quadratic formula.
- Some students should be able to derive the quadratic equation by completing the square and use it to solve complex problems.